Operating mechanism



H. J. WEBB ETAL OPERATING MECHANISM Filed Oct. 10, 1942 Oct. 30, 1945.

ME; I a: I a m INVENTORS GeorgeE Sa /20 62; and Hrbrt Webb. y 2/ Argo n'ui WITNESSES:

Patented Oct. 3.0, 1945 OPERATING MECHANISM Herbert J. Webb, Forest Hills, Pa., and George E.

Saunders, Arlington, Va., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 10, 1942, Serial No. 461,562

14 Claims.

This invention relates to improvements in circuit interrupters, and more particularly to fluid pressure operated structures for controlling the flow of arc extinguishing blasts of gas in circuit interrupters of the gas blast type.

One object of the invention is to provide a circuit interrupter with an improved fluid pressure operating mechanism for a blast valve forcontrolling an arc extinguishing gas blast.

Another object of the invention is the provision of a circuit interrupter of the gas blast type with a separate fluid pressure operated mechanism for effecting high speed opening and closing of the blast valve.

Another object of the invention is the provision of an improved compressed air operating mechanism operable in each direction by compressed air to quickly actuate an element between two opposite positions, the mechanism having a very simple air operating system which utilizes only a single pilot valve for controlling operation of the mechanism in both directions.

Another object of the invention is the provision of a circuit interrupter of the gas blast type with an improved fluid pressure operated blast valve mechanism wherein fluid pressure will be applied to operate the blast valve for controlling the arc extinguishing gas blast, to open and to closed positions by a single electromagnetically operated valve.

Another object of the invention is the provision of an improved fluid pressure operated mechanism which is simple, fast and reliable in operation, and inexpensive to manufacture.

The novel features that are considered characteristic of the invention are set forth in particular in the appended claims the invention itself, however, both as to structure and operation, together with additional objects and advantages thereof will best be understood from the following detailed description when read in conjunction with the accompanying drawing, in which:

Figure 1 is an elevational view, partl in section of a blast valve operating mechanism for a circuit interrupter of the gas blast type,

Fig. 2 is an elevationalview in reduced scale and partly in section showing a portion of the contact structure of a circuit interrupter and the blast valve for controlling the arc extinguishing as blast.

The circuit interrupter to which the improved blast valve operating mechanism is adapted to be applied is of the type disclosed in U. S. Patent No. 2,288,472 issued June 30, 1942, to John B,

MacNeill and A. H. Bakken, and assigned to the assignee of the instant invention.

Referring to the drawing, a part of the supporting framework for supporting the interrupter mechanism is designated by the reference numeral l. Rising from the framework l is a pair of insulating supports 3, onl one of which is shown. The upper ends of the supports 3 carry an arc extinguishing structure 5, the lower portion only of which is shown. The are extinguish.- er 5 is also supported by a tubular conduit and insulator l, the lower end of which extends through a suitable opening in a channel member 9 carried by the cross members of the frame I. The tubular support I is secured to the channel member 9 by means of a pair of cooperating clamp rings H and I3, the outer one of which rings is bolted to the channel member.

The are extinguisher 5 houses the interrupter contact structure comprising a stationary contact l5 and a cooperating movable contact H. The movable contact I! is pivotally supported at l9 to a conducting bracket 2|, which may be supported on the tubular insulator l and the insulating support members 3. The stationar contact I5 is provided with a terminal connector 23 for making an external connection to the interrupter, and the conducting bracket 2| is provided with a similar terminal connector 25. The electrical circuit through the interrupter extends from the terminal 23 through the stationar and movable contacts I5 and H, the conducting bracket 2| and the terminal connector 25.

The movable contact I1 is actuated to open and closed positions by means of an insulating operating rod 2! which, in turn, is operated by a suitable compressed air operated mechanism, not shown herein. The operating mechanism may be of any suitable type, preferably comprising a cylinder having a piston therein and to which compressed air is admitted by means of suitable control valves to efiect the opening and closing movements of the movable contact l'l.

During the opening operation of the interrupter, an arc is drawn between the contacts l5 and l! across the discharge end 35 of the tubular insulator l which, in addition to serving as a support for the arc extinguisher 5, also serves as a conduit to direct a blast of arc extinguishing gas from a storage tank 33 upon the arc in the arc extinguisher 5. The are extinguishing blast from the tank 33 is controlled by a blast valve 31 disposed within a valve housing 39 secured by means of bolts 42 to a short, flanged conduit 4! extending from the tank 33. The valve housing 39 has a through passage 43 therein in axial alignment with the conduit 4| and with the insulating conduit 1. The valve 3'! is adapted to seat against the lower side of the housing 39 to seal the passage 43.

In order to conserve compressed gas and to obtain as many arc extinguishing blasts as possible from. a single. charging of the. tank 33; it is. desirable that each arc extinguishing blast be of as short a duration as is possible, and that the valve be quickly closed as soon as the arc is extinguished. The arc is extinguished shortly after. the contacts separate and a considerable time before the moving contact reachessfuli open position. In actual practice, the blastvalve 3 11' may be open for a. very brief duration and then may be quickly reclosed. In order to obtain this'quick automatic opening and closing of the valve 31., the. valve operating mechanism, shown in Fig. 1 of the drawing, is provided.

Operation. of. the valve. 31 for controlling the blast of air is effected. by a. rocker arm 41, operatively connected to the. valve and. secured to a crossshaftlll! journalled in the. valve housing 39. The. portion of the-rocker arm extending outside thevalve housing is connected by means of a. pin and. slot connection 5f to the. upper end of a piston rod 53 extending into anoperating cylinder 55 and secured at its. lower end. to an operating piston 51.. The. top- 59 of the. cylinder is formed integral. with the. cylinder walls, and. the bottom of. the cylinder is.- closed by means: of a plate. 6| suitably secured to the. cylindenas for instance, by welding.

The piston 51 ismovablevertically in the cylinder 55.130: open and. close the valve 3.1'by. means of compressed. gas admitted. to the. lower end and to the upper end of. the. cylinder. respectively by the control. of a single electromagnetically operated pilot. valve. 63.. Compressed. air is. admitted. to thelower end. oi the. cylinder 55 when the pilot. valve. is opened, thereby operating. the blast valve to. open. position. When. the. pilot. valve closes, compressed air. is. automatically admitted to the. upper endof the cylinder 55=through a. pneumatically operated'valve. 6 5 and. the. compressed air quickly returns. the blast. valve. to closed. position. The. valve. 63 is. mounted. in a. valve housing. Bl. which is divided. into. three chambers. The lower chamber is connected by means of a. pipe 69 to: aeompressedl air. reservoir H=.,.which may or may not: be the same: as, or connected.to,. the reservoir 33 of Fig. 2-. The center chamber is. connected by meansof a pipe'ld to thealower. end of. the operating. cylinder 55 below the. piston 51,. and the upper chamber of: thehousing 61 is connected. by a port 1-5 to atmosphere. The inlet valve 83. is mounted. on the lower end of. a valve stem l1 upon which is. also mounted an exhaust. valve. 19. The valvev 63 isadapted to be operated. to the open position. and. the valve 19; is adapted to be simultaneously operated to the closed. position by energization or an. electromagnet indicated generally at 8l... Opening, oi the valve 63. connects thelowerend. of the cylinder 55 to. the source ll of. compressed. gas,. and closing of the. valve 19. closes the. exhaust port.

The pneumatically operated-valve 65. islmounted in a cylinder 83. formed in a. housing 85 secured to the. closure plate. 5.1.. The lower end of the cylinder 83 is enlarged to'form. an inlet. chamber 87!.- which is connected by means of a pipe. 89 to the air reservoir H. The inlet chamber 81. is. also connected to: the upper endof the operating, cylinder. 55 by means of apipe 9!. lhe. upper end.

of the valve cylinder 83 is connected by means of a pipe 93 and the pipe 13 to the middle chamber of the pilot valve housing 61'.

The valve is mounted on the lower end of a valve stem 95 which extends through an opening in housing and has an exhaust valve member 9'! reciprocably movable in a cylinder 99 formed in the. upper end of the housingBEi The cylinder 93 is connected by means of a pipe PM and the pipe 9! to the upper end of the operating cylinder 55; and is connected to atmosphere by a port I03 in. alignment with the pipe I01. When the interrupter contacts and the operating piston 51 are in the closed position, as shown in the drawing;.the.valve 3 521s held in the closed position and thevalve 91 is held in the open position by means of aplunger I 65 slidably mounted in the bottom closure plate 6-! of. the cylinder 55, the plunger N5 being held in the position shown by the piston 51 which is biased to the closed position by a spring. It] coiled. about the. operating. rod 53 and compressed between the upper portion. 59- of the cylinder and the top. oi the. piston 51... The spring lfll' also serves. to maintain the blast. valve- 31 (Fig. 2) in closed. position when. the. valves 63 and 65 are closed, shutting. oii the supply of compressed. gas. from the. reservoir ii. A spring IE9. surrounding, the plunger [-05 within. the cylinder. 99' and compressed, between. a head Ill. on the upper end of. the plunger, and the plate. 6| serves to move the plunger upwardly upon upward, or opening. movement of. the piston. A pin H3 extending through. an opening. inthe plunger below. the plate 8'! is provided to limit the. upward travel. of the plunger.

The. operation. of. the. device. is. described as fol-- lows: When the. electromagnet 8|. is energized, simultaneously with the initiation of an opening operation of thebreaker by means ot a Well knownprotective relay (not shown) upon-.theoccurrenceof. an. overload in. the. circuit. controlled by the interrupter, the valve. 63 is opened and the valve 19- closed'... Opening, of. thevalve63 admitscompressed gas. from the reservoir. Ll through the pipe 6.9-.

. the. valve. 63. and the. pipe. 13. to, the cylinder 55 belowthe. piston 51. to operate the piston upwardly and open theblast-valve 37.. At the same time, opening of the valve 63 also. admits com-- pressed gasto the cylinder 83.ab.ove the pneumatic. valve '65 through the pipe 93. Since therarea. of. thetop of the valve 6.5 is greater than. thearea of the-bottom, the pressurev applied tothe top-thereof willmai-ntain. the valve 65. closed. during. the opening movementoi the. piston 51.. As. the piston. 57. moves upwardly the. gas in the. cylinder above. the piston is exhausted. to atmosphere. through the. pipes, HI. and ml. the. cylinder 99. and the exhaust. port. H13. As. soon as the circuit is. interrupted. the magnet 8| is. deenergized whereupon a. spring. l 15 operates the valves 63. and 79, respectively,. to the closed and open positions. Thisshutsoff the supply of compressed air. to the cylinder 55 and to the top of the valve 65 and at the same. time. connects these parts to. atmosphere through the valve 19. andthe exhaust port. "[5. The pressure. beneath the. piston 51 and on the. top of the valve 6.51s thereloi. relieved. and the compressed air acting on the lower end. of the valve. 65 immediately forces this. valve upwardly admitting. compressed air through. the. pipe Si tn the cylinder 55 above the piston 51. At the same time, upward movementof the valve 65. moves the valve 91 upwardly to.. close the; exhaust port I03 and the pipe 19!. Thecompressed air admitted to thecylinder. drives the piston. 51 quickly downwardly to close. the.

blast valve 31. As the piston 51 approaches its closed position, the bottom thereof engages head III of the plunger I05, which was raised by the spring 109 as the piston moved upwardly, and thereby thrusts the valves 91 and 65 downwardly to close the valve 65 and open the exhaust port I03.

From the foregoing description, it will be apparent that there is provided an improved operating mechanism of the fluid pressure type comprising a piston reciprocably movable within a cylinder. Fluid pressure for operating the piston is admitted alternately to opposite ends of the cylinder to operate the piston quickly in opening and closing directions, by means of two separate inlet valves, one of which is operated by an electromagnet and the other inlet valve is operated automatically by fluid pressure under the control of the magnetically operated valve and the piston.

It will be obvious that the operating mechanism may be used to operate other mechanisms, for instance, by providing a' suitable connection, the mechanism may readily be adapted to operate the movable contact of the circuit interrupter to open and close the circuit.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details thereof may be made without departing from some of the essential features of the invention, and that come within the scope of the appended claims.

We claim as our invention:

1. An operating mechanism comprising a fluid motor operable between two extreme positions, an inlet valve operable to admit fluid under pressure to said motor to cause operation of said motor to a first extreme position, a second inlet valve operable by fluid pressure mechanically independently of said first named inlet valve to admit fluid under pressure to said motor for operating said motor to a second extreme position, and means op erable by the motor when said motor moves to said second extreme position to positively close said second named inlet valve.

2. An operating mechanism comprising a cylinder and a piston movable therein between two extreme positions, a source of fluid under pressure, an inlet valve operable to admit fluid under pressure to said cylinder to operate the piston to one of said extreme positions, a second inlet valve operable to admit fluid under pressure to said cylinder to operate said piston to a second extreme position, and means operated by the piston to maintain the second named inlet valve in closed position when the piston is in said second extreme position, said second named inlet valve being maintained in closed position during movement of the piston to saidfirst extreme position by fluid pressure admitted thereto by opening of the first named inlet valve.

3. An operating mechanism comprising a cylinder and a piston movable therein to two extreme positions, a source of fluid under pressure, an inlet valve operable to admit fluid under pressure to said cylinder for operating the piston to one of said extreme positions, a second inlet valve operable by fluid pressure to admit fluid under pressure to the cylinder for operating the piston to a second of said extreme positions, means controlled by the piston for maintaining said second valve closed when the piston is in said second position, and a connection for admitting fluid under pressure from said first named inlet valve to said second named inlet valve for maintaining said second named valve in closed position during movement of the piston to said first extreme position.

4. An operating mechanism comprising a cylinder and a piston movable therein to a first and a second extreme position, a source of gas under pressure, an inlet valve operable to admit gas under pressure to one end of said cylinder for moving said piston to said first extreme position, a second inlet valve operable to admit gas under pressure to the other end of said cylinder for mov ing the piston to said second extreme position, a connection for applying gas pressure to one side of said second named inlet valve for operating said second inlet valve to open position, means operable by said piston for maintaining said second named inlet valve in closed position while said first named inlet valve is in closed position, and a connection for admitting gas under pressure to the other side of said second named inlet valve when said first named inlet valve is opened for maintaining said second named inlet valve closed during movement of the piston to said first extreme position.

5. An operating mechanism comprising a cylinder and a piston movable therein between a first and second position, a closing control valve operable to admit fluid pressure to said cylinder for moving the piston to said first position, means for applying fluid pressure to one end of said closing control valve to operate sa d closin valve to open position, means operable by the piston for holding said closing control valve in closed position while said piston is in said first position, said means being operable upon movement of said piston to said second position to permit opening of said closing control valve, and an opening control valve operable to admit fluid pressure to the cylinder for moving the piston to said second position and for simultaneously admitting fluid pressure to the other end of the closing control valve for holding said closing control valve in closed position during movement of the piston to said second position.

6. An operating mechanism comprising a cylinder and a piston movable therein to a first and to a second position, a source of fluid under pressure, an inlet valve operable to admit fluid pressure to said cylinder for moving the piston to said first position, means for applying continuous flu d pressure to said inlet valve tending to operate said inlet valve to open position, a member extending into said cylinder and engageable by the piston to hold said inlet valve in closed position against the fluid pressure, and a second inlet valve operable to admit fluid pressure to the cylinder for moving the piston to said second position, sa d second named inlet valve also admitting fluid pressure to the first named inlet valve to hold sa d first named inlet valve closed during movement of the piston to said second position.

7. An operating mechanism comprising a cylinder and a piston movable therein between a first and second extreme position, a source of fluid under pressure, means biasing said piston to said first extreme position, an inlet valve for admitting fluid pressure to one end of said cylinder to effect movement of the piston to said first extreme position, means controlled by said piston durin movement thereof to said first extreme position for closing said inlet valve, said means being effective when the piston is in said first extreme position to maintain said inlet valve in closed position, and a second inlet valve operable to simultaneously admit fluid pressure to the other end of the cylinder and to the first named inlet valve to: client; movement of; the piston to said; second extreme position and to maintain said first named inlet valvein closed position during: movement. of the: piston to: said second: extreme position.

8'. An operating mechanism comprising a piston movable between two extreme positions, a cylinder within which said piston moves, an electromagnetically operable valve for admitting fluid pres.- sure to one end of thecylinder toieffect movement of the piston to oneextremeposition, and apneumatically operated valve for admitting fluid pressure to the other end: of said cylinder toeiiect movement of. said piston to-a second extremeposition, said pistonv in said. second position holding said pneumatically operated valve closed, andsaid electromagnetically operated valve being efiective when opened to admit fluid pressure tov maintain. the pneumatically operated valve in closed position during movement of the. piston to said one extreme position.

9'. An. operating mechanism comprising a cylinder and a. piston movable therein between two extreme positions, a source of gas under'pressure, an inlet valve operable to admit gas pressure to one end of said cylinder to ffect movement of said piston to one position, one end of said inlet valve having a smaller area than the other end, means connecting said source of gas under pressure to the smaller end of said inlet valve for applying a continuous gas pressurev tending to open said valve, means in said cylinder engageable by said piston for holding said inlet valve closed when the piston is insaid one position, said means permitting said gas pressure to open the inlet valve when the piston moves to a second position, and a second inlet valve operable to admit gas pressure to the other end. of said cylinder to effect movement of said piston to said second position, said second inlet valve being efiective when operated to admit gas pressure to the larger end of the first named inlet Valve to maintain said first named inlet valve closed during the movement of the piston to said second position.

10. In a circuit interrupter, an operating mechanism comprising a fluid motor having a normal position and operable to do work in two directions, a source of fluid pressure, an inlet valve for controlling the admission of fluid pressure to said motor for operating said motor in both directions, a single electromagnet for controlling said valve, said valve when open admitting fluid pressure to the motor to operate said motor in one direction, means separate from said valve and operable upon closure of said valve to admit fluid under pressure to the motor for operating said motor in the other direction, and spring means to maintain said motor insaid normal position when said inlet valve is closed, said motor in said normal position preventing operation of said separate means.

11. In a circuit interrupter, an operating mechanism comprising a fluid motor having a normal position, a source of fluid under pressure, means including a single electro-magnetically operable valve for controlling the admission of fluid pressure to the motor to effect movement of said motor, said valvewhen open admitting fi'uidpres sure. to said motor tov efiect movement: of said motor away from said normal positiomand. meansseparate. from. said valve and operable automatically upon closure of: said valve toadmitfluid pres-- sure to the motor to operate said. motor to said normal position, said motor in said normal posi-- tion preventing operation of said separate means.

12. In a circuit interruptenan operating mechanism comprising a piston and a cylinder inwhich said piston operates, said piston having a normal position in one end of the cylinder, an electro magnetically operable valve for controlling the. admission of fluid pressure to the cylinder toeffect movement of the piston, said valve bein effective when open toadmit fluid pressure to one end of the cylinder to eflect movement-0f the pieton from the normal position to the other end of the cylinder, and means separate from said valve and automatically operable uponcl'osure'of said valve to admit fluid pressureto. the other end of said cylinder, to move the piston back tosaid not mal position, and means engageable bythe piston in the normal position to prevent operation of said separate means.

13. In a circuit interrupter, an operating mechanism including a piston, a cylinder within which said piston moves, an electromagnetically oper able valve for admitting fluid pressure to oneend of the cylinder to effect movement of the piston. in one direction, a pneumatically operable valve for admitting fluid pressure: to the other end of said cylinder to effect movement of the piston in the other direction, said electromagnetically operated valvebeing effective to admit fluid pressure to maintain the pneumatically operated valve in closed position during movement of the piston in said one direction, and means operated by said piston when said piston is operated in said other direction to close said pneumatically operated valve, said piston and said means maintaining said pneumatically operated valve closed when said electromagnetically operated valve is closed.

14. An operating mechanism compris ngan operating piston and a cylinder within which said piston is movable to a first and second extreme position, spring means normally restraining said operating piston in said second extreme position. a source of fluid under pressure, means including an inlet valve operable to adm t fluid underpressure to said cylinder for moving said operating piston to said first extreme position. a second inlet valve automatically operable by fluid pressure HERBERT J: WEBB. GEORGE E. SAUNDERS. 

